Move distance field generation to the glyph cache

src/gpu/SkGrFontScaler.cpp

Index: src/gpu/SkGrFontScaler.cpp
diff --git a/src/gpu/SkGrFontScaler.cpp b/src/gpu/SkGrFontScaler.cpp
index 8fdae48a2adde48c7f5f1ffd42e7f8299ddf461f..f49fd67035c6bff3e2c0574a4fb856d6b4e85b41 100644
--- a/src/gpu/SkGrFontScaler.cpp
+++ b/src/gpu/SkGrFontScaler.cpp
@@ -10,6 +10,7 @@
 #include "GrTemplates.h"
 #include "SkGr.h"
 #include "SkDescriptor.h"
+#include "SkDistanceFieldGen.h"
 #include "SkGlyphCache.h"
 
 class SkGrDescKey : public GrKey {
@@ -108,8 +109,19 @@ bool SkGrFontScaler::getPackedGlyphBounds(GrGlyph::PackedID packed,
                                               GrGlyph::UnpackFixedX(packed),
                                               GrGlyph::UnpackFixedY(packed));
     bounds->setXYWH(glyph.fLeft, glyph.fTop, glyph.fWidth, glyph.fHeight);
+
     return true;
+}
+
+bool SkGrFontScaler::getPackedGlyphDFBounds(GrGlyph::PackedID packed,

[robertphillips, 2014/04/11 14:13:00]

Align or fit on one line?

[jvanverth1, 2014/04/11 17:54:14]

Done.

+                                          SkIRect* bounds) {
+    const SkGlyph& glyph = fStrike->getGlyphIDMetrics(GrGlyph::UnpackID(packed),

[robertphillips, 2014/04/11 14:13:00]

align?

[jvanverth1, 2014/04/11 17:54:14]

Done.

+                                              GrGlyph::UnpackFixedX(packed),
+                                              GrGlyph::UnpackFixedY(packed));
+    bounds->setXYWH(glyph.fLeft, glyph.fTop, glyph.fWidth, glyph.fHeight);
+    bounds->outset(SK_DistanceFieldPad, SK_DistanceFieldPad);
 
+    return true;
 }
 
 namespace {
@@ -190,6 +202,24 @@ bool SkGrFontScaler::getPackedGlyphImage(GrGlyph::PackedID packed,
     return true;
 }
 
+bool SkGrFontScaler::getPackedGlyphDFImage(GrGlyph::PackedID packed,
+                                           int width, int height,
+                                           int dstRB, void* dst) {
+    const SkGlyph& glyph = fStrike->getGlyphIDMetrics(GrGlyph::UnpackID(packed),

[robertphillips, 2014/04/11 14:13:00]

align?

[jvanverth1, 2014/04/11 17:54:14]

Done.

+                                              GrGlyph::UnpackFixedX(packed),
+                                              GrGlyph::UnpackFixedY(packed));
+    SkASSERT(glyph.fWidth + 2*SK_DistanceFieldPad == width);
+    SkASSERT(glyph.fHeight + 2*SK_DistanceFieldPad == height);
+    const void* src = fStrike->findDistanceField(glyph);
+    if (NULL == src) {
+        return false;
+    }
+

[robertphillips, 2014/04/11 14:13:00]

At a higher-level why are we copying out here?

[jvanverth1, 2014/04/11 17:54:14]

The short answer is: to match getPackedGlyphImage. The long is that I noticed
this as well and the src pointer could be returned directly. The only issue is
that might make the cache less thread-friendly (i.e. what happens if you request
a distance field and another thread deletes it before you copy it to the
driver).

+    memcpy(dst, src, width * height);
+
+    return true;
+}
+
 // we should just return const SkPath* (NULL means false)
 bool SkGrFontScaler::getGlyphPath(uint16_t glyphID, SkPath* path) {